Carver Owners Forum

To see my latest thoughts on early system testing, see this post: viewtopic.php?p=67100#p67100

Generators have been the bane of my boating existence. We had a new boat built for us years ago and even it had generator issues. In today's world I feel like technology has gotten to the point that the generator is no longer necessary to have heat, air conditioning, and all the other AC based loads we enjoy. I've had an electrical upgrade on my projects list for quite some time, but it was fairly low in priority since everything was working.

A few weeks ago the starboard engine wouldn't start and it sounded like a weak battery. I at least learned how the boat manages paralleling the batteries without switches, which is probably improper use of that term. The port engine started and then after a few minutes I was able to start the starboard. This makes sense to me because there is a two alternator/three battery bank battery isolator on board. Once port started, that alternator was feeding enough extra juice to "jump" starboard. Figuring it was a bad battery (it is roughly 3 years old which is all I seem to get here in Florida), I took the battery out to have it tested. It tested good. While normally people would be happy with that result, for us boaters it means that something more expensive is working against us.

I re-installed the battery and tried to start starboard. Slow crank and no start. Start port, wait a bit, and starboard starts fine.

I noticed once the engines were started, the volts were only in the 11.0 range. I had about 13.8 without the engines running. What I found was that the battery isolator is open from A1 to all 3 banks. A1 is most likely starboard. So when the port engine is running, it is feeding all three battery banks, but when starboard is running its alternator can't feed anything.

Diode isolators being pretty old technology, I went in search of something different. DC-DC converters or Argofets seemed to be the way to go. I called the local Victron dealer who put me in touch with The Yacht Rigger. We had a great conversation about what happened and what I'd like to accomplish. He quickly steered me away from Argofets since the ultimate goal is to go full lithium without a generator.

The goals of the project:
1. Run all house loads while underway using the engines. I already need to have two powerful engines running so why have to also have the generator running?
2. Be able to remain comfortable overnight during August in Florida without running any engines.
3. Retain or improve on existing redundancies.
4. A phased approach that doesn't result in any wasted new components, provides as much benefit as early as possible, and minimizes upfront costs.

The initial thinking:

• DC-DC converters now to address the battery isolator issue.
• High output alternator(s).
• Victron LiFePO batteries for house bank.
• Two Victron Multiplus charger/inverters. My requirements would need either two small or one large Multiplus. Two smaller ones are easier to work with.

The Yacht Rigger will be sending me a plan next week with more details. Once this project is fully completed, the generator will essentially be redundant and can be removed. Optionally, we could look at using Quattro instead of Multiplus and keep the generator, but I don't think that really buys anything. Not having a generator would make that space available for either more storage or more batteries.

So far this year is shaping up to have a lot of projects.

"So far this year is shaping up to have a lot of projects"

And sounds like big expenses

Just curious, what kWh are you targeting for the LiFePo4 house bank?

And sounds like big expenses

Bust Out Another (10) Thousand? We plan to keep the boat for a long time, so spending now will maximize how long we can enjoy the changes. I have no illusion that these projects can be evaluated on any return on investment other than personal enjoyment. My wife and I discussed that if we put this money into this boat then we are not looking to buy another one, even if one of our dream boats were to come available at a price we could afford. Carver was always one of my dream boats anyway. I sure would like to have diesels, but otherwise the 360 is about perfect for us.

Just curious, what kWh are you targeting for the LiFePo4 house bank?

As much as possible eventually. I think to start we'll be in the 12kWh usable range. This would be 4x Victron 12v 300Ah and should give us about 6 hours with full house loads if I calculated correctly. The main loads are the two air conditioners which are a little under 20A @ 120v/200A @ 12v combined when running. I can double the run time if I only use one air conditioner or the other, and I based my calculations on the compressors running continuously. In August in Florida at the temps we like to keep the boat it seems like the compressors run the whole time.

According to Victron, "the maximum number of batteries in one system is 50, which results in a maximum energy storage of 192 kWh in a 12V system and up to 384 kWh in a 24V and 48V system." I'm pretty sure we can't fit 50 batteries on a 36 foot boat. If we can get to 20+ hours on the batteries that will be ideal.

If I were you, I would get another opinion from another marine electrician. 10K sounds high. Good luck! er

No need for Victron batteries as you definitely are paying a premium for the name. The electronics YES but not the batteries.

Here is a good example. Eco-Worthy which is a well known name when it comes to Solar. They are becoming less expensive than AGM as time goes by.

https://www.amazon.com/ECO-WORTHY-12V-280Ah-2Pack-Phosphate/dp/B0CKT2J3M9/ref=sr_1_4?crid=1AD880XVEHHJP&dib=eyJ2IjoiMSJ9.Yo9AbWVT-Uvr63r2qZkL0hPoKXqenE8kYDRMmGRUONm6jvH7Xg-KpM_u77SDEgP45hjERYPfpPzHAgu39zW6pbkkPNvebgInvi5MmRaJACPMGEGQcojyhxP1Opq3pMb8HD3eYz4UKaLUCMHI_oP_D-nASOy0__JRChD0sBWBRhK_K0bDsDInZHCFobjjF1DnlhgxqLpUFFqjjmOd-2K617E70eCTIwHXf_LQGJ2qXvY.w2uQKJugHl7O5nQPkDIB_5j2MpEf9dV25rpOj8kZFZQ&dib_tag=se&keywords=280ah%2Blithium&qid=1736702774&sprefix=280ah%2Blithium%2Caps%2C97&sr=8-4&th=1

Check out epoch batteries. Best built/value batteries I have found. I have two of the 460ah. These are internally fused, UL listed and all… Everything is made in china now a days but this is a US backed company.

You’re not running air conditioning for long without a massive battery bank. I run the aft state room unit overnight for sleeping out at anchor… You need to charge these batteries and will take a long time with a large bank and you’ll need thousands in battery chargers. A 3k multiplus will put out 120a ideal conditions. I use that and another 75a charger and it still takes 4 hours of generator run time to fill them back up after discharging to 20% SOC.

I moved the aft state room ac unit to line 1, added a small pump and that’s the only ac I run off the batteries. I only inverted line 1 with a single 3000 Victron multiplus. The rest of the ac runs on line 2 and off generator or shore power. If no ac is needed I can go several days powering everything off the inverter.

Two weeks have gone by and I haven't received the plan or the estimate.

Conceptually this seems like a fairly straightforward DIY job, but one that will take a considerable amount of time. I liked the idea of having an ABYC certified technician doing the project to finish it quickly, but now I'm considering paying for the plan/consultation and doing the work myself. Has anyone taken on this type of project themselves?

We're back on. The gentleman I have been talking to had an emergency to attend to, but we have a plan now.

The gas generator is going to be replaced with a fabricated "battery unit" (my description) consisting of a 900Ah 24v LiFePO battery bank and Victron Multiplus 24/5000. This will give us plenty of stored power for a night at anchor running all the modern amenities in the sweltering heat of August in Florida without having to worry about the generator droning along all night. Thankfully where we have anchored we have been alone so didn't have to worry about bothering the neighbors. Now the power will be silent anyway.

Arco is coming out with 7KW alternators. This guy worked with Arco's engineers in the R&D phase, so we'll be one of the first customer boats with the tech. There is a test fleet of about 20 installs. At idle we should be generating about 6KW and at cruise we'll be close to 14KW. There is plenty of redundancy since the entire boat can basically run off only one of the alternators if the other fails.

The existing 12v system will remain and be charged by the 24v system. I just replaced the 12v AGM house battery about a year ago, so we'll leave that in place. When it eventually dies, it will basically be a drop-in replacement to go to a 12v LiFePO with just an update on the charge profile.

The last update, which I'm a bit on the fence, is changing the air conditioners to variable speed units. The salon air conditioner is only a few years old. The stateroom air conditioner is old and loud, but still works. The cost for the switch is fairly reasonable though since so much other work is being done. This will save about 20% or so in power demand.

And the whole system will be expandable in the future, so basically a "buy once, cry once" situation.

Scheduling is looking like March timeframe. I'll post the before and after pics, along with any lessons learned, once we get started.

I see we have similar boats and I’ve considered ditching the genny if/when it has a major issue. Via a decent house bank and possibly adding a Jackery for the appliances (coffe/mico/tvs) I think it’s totally feasible but I’m still struggling to understand just how much battery capacity it really takes to run 1 or all three of the ac units all night. Can you tell me what usage you calculated for just the aircon units? Do the new dc or variable units really reduce that number enough to make switching worth the $$? Very interesting post. Thanks for sharing!